The present invention relates to an abrasive pad and a polishing method advantageously applicable to wafers for the production of semiconductor devices.
There is an increasing demand for technologies capable of flattening the surfaces of wafers with accuracy in order to implement the highly integrated, dense arrangement of semiconductor devices. A CMP (Chemical Mechanical Polishing) method, which is one of the state-of-the art flattening technologies, presses a wafer against an abrasive pad and polishes the wafer while feeding slurry or chemical polishing fluid. The CMP method, however, cannot feed slurry uniformly to the entire surface of the abrasive pad and therefore cannot uniformly polish it. Further, the slurry holding ability of the pad is too low to promote the efficient use of the slurry. Moreover, because the slurry holding ability of the pad is short, the feed of the slurry to the pad surface becomes short when the pad spins at a high speed under a high pressure. This prevents the pad from polishing the wafer at a high speed under a high pressure.
Technologies relating to the present invention are disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 62-39173,
It is therefore an object of the present invention to provide an abrasive pad and a polishing method capable of enhancing uniform polishing and high speed, high pressure polishing while promoting efficient use of the slurry.
In accordance with the present invention, in an abrasive pad including a pad body capable of spinning for polishing a workpiece pressed against the pad body, a number of grooves for slurry are formed in the surface of the pad body and intersect each other to form a number of projections aligned in the horizontal and vertical directions and each having a polygonal shape, as seen in a plan view. One of the projections faces each groove in the lengthwise direction of the groove.
Also, in accordance with the present invention, in a polishing method using an abrasive pad including a pad body that is capable of spinning for polishing a workpiece pressed against the pad body, the abrasive pad is caused to spin at a speed of 100 rpm to 150 rpm while polishing the workpiece.